Analysis of water and nutrient flows in the Sava River Catchment fills gaps in scientific knowledge of the area

In her PhD thesis, Lea Levi has studied the Sava River Catchment, an area that has previously been missing evaluation of long-term hydro-climatic and nutrient loading changes. The project led to new discoveries about the area as well as the development of a data-based methodology for detection of nutrient input, delivery, retention and loading that can be applied in any river catchment.

Lea Levi (Photo: Private)

What is the topic of your Doctoral Thesis?

The topic of my thesis is data-driven analysis of water and nutrient flows in the Sava River Catchment and comparison of its results with other world regions. In simple words my thesis deals with water and nutrient related changes in the landscape and distinguishes their drivers by primarily using the observed data of the past to present periods but also addresses future projections of global climate models.

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Why did you choose this topic?

Sava River Catchment is an area that provides water, food and energy for more than eight million people living within it. It is also an important contributor to the Danube River Basin and thus also the Black Sea. Geo-politically it is an interesting region that is shared among six countries and also an area that has been missing evaluation of long-term hydro-climatic and nutrient loading changes. So basically our aim was to fill those gaps considering scientific knowledge so that they can further be used in practice for various mitigation measures. Also, we compared Sava results and methodologies with other world regions in order to address their possible transferability and generality so they could possibly be used also in other catchments.

What are the most important results?

There are a few. First we discovered that the whole Sava River Catchment, considering its hydro-climatic changes and behavior is a combination of two different signals. One is unregulated and the other is dominated by hydropower developments that have started around 1950s.

Second we successfully developed a data-based methodology for detection of nutrient input, delivery, retention and loading that can be applied in any river catchment where basic data of discharge and nutrient concentrations are known. This is particularly important for catchments with limited data availability that are very common in the world. Yet, even for those catchments it is necessary to find the ways to detect possible pollution hotspots and their drivers and this methodology manages to do it to a certain extent. Finally, the analysis of the water changes projections for the future indicates possible water scarcity within the Sava River Catchment, so definitely something to think a bit more about!

Did you come across something unexpected during your thesis research?

It took me almost two years to collect the needed data and that is a long time in terms of PhD studies. This area went just 20 years ago through a civil war and still has complex socio-political situation so it was reasonable to expect certain difficulties considering the data collection for Sava. Yet that made the work on this thesis quite challenging but also interesting as I had to find new ways to accomplish my goals which in the end proved to be instructive and fruitful.

Who will benefit from your results?

I hope primarily people living within the Catchment. I hope that the institutions in-charge of the water and land use of the Sava River Catchment will find our results useful as a guiding tool for mitigation measures and policies that are needed for good and sustainable operation of the whole Catchment.

What will you do next?

Four days after my defense I started to work as a consultant in WSP Sverige AB. I will be working with water related issues and hopefully also contribute with research development. So, am happy I can continue working with water, which has been very important for me and also use the knowledge that I got during my PhD studies at KTH. It is something new now in my life and it feels like exciting times are on their way!

Lea Levi defended her PhD thesis Data-driven analysis of water and nutrient flows - Case of the Sava River Catchment and comparison with other regions in June 2017 within the research area Land and Water Resources Engineering.